Apparatus for the vibratory finishing of workpieces

ABSTRACT

A work container is filled with a polishing or grinding medium and workpieces are mounted to an auxiliary device which transports the workpieces into, through and out of the medium. A vibrator is mounted to the container for vibrating the polishing medium and circulating it in a predetermined direction through the container. The auxiliary device can be moved by the circulating medium or by independent drive means. A secondary work container can be mounted to the interior of the main container and a mixture of small workpieces and polishing medium can be fed through the secondary container while large pieces are carried through the main container by the auxiliary device.

[451 May 16, 1972 APPARATUS FOR THE VIBRATORY FINISHING OF WORKPIECES[72] Inventor: Georg Altenstaedter, Griefstedt, Germany [73] Assignee:Terry Lewis, Berlin, Germany a part interest [22] Filed: Mar. 24, 1970[21] Appl. No.: 22,268

[30] Foreign Application Priority Data May 27, 1969 Germany ..P 19 26920.6

[52] U.S.Cl ,.51/7,51/l7,51/317 [51] Int. Cl. ..B24b 19/00, B24b 1/00[58] Field oISearch ..5l/7,17,18,19,163,164,

[56] References Cited UNITED STATES PATENTS 3,371,449 3/1968 Olson et a1....51/7 3,539,117 11/1970 Sjogren ....51/7 3,464,163 9/1969 Ferrara........5l/7 2,997,813 8/1961 Brandt ..51/7 2,720,730 10/1955 Kroger........5l/7 2,891,357 6/1959 Davidson ..51/7

2,803,093 8/1957 Diehl et al.

2,480,238 8/1949 Hammond et al. 51/19 569,090 10/1896 Cox et a1 51/192,337,453 12/1943 Corey et a1. .51/6 392,556 11/1888 Harris .51/6

2,600,282 6/1952 Strong 2,682,732 7/1954 Hanrahan et al. ..51/164471,284 3/1892 Walters et al ..51/19 Primary Examiner-William R.Armstrong Anorney-Townsend & Townsend [5 7] ABSTRACT A work container isfilled with a polishing or grinding medium and workpieces are mounted toan auxiliary device which transports the workpieces into, through andout of the medium. A vibrator is mounted to the container for vibratingthe polishing medium and circulating it in a predetermined directionthrough the container. The auxiliary device can be moved by thecirculating medium or by independent drive means. A secondary workcontainer can be mounted to the interior of the main container and amixture of small workpieces and polishing medium can be fed through thesecondary container while large pieces are carried through the maincontainer by the auxiliary device.

13 Claims, 10 Drawing Figures PMENTEDMAY 16 I972 SHEET 1 OF 5 INVENTORGEORG ALTENST'ADTER ATTORNEYS PATFNTEDMM 16 I972 SHEET 2 BF 5 INVENTORGEORG ALTENSTKDTER BY WW7 ATTORNEYS P ATE'NTEDMAY 16 1972 SHEET 0F 5INVENTQR GEORG ALTENSTADTER ATTORNEYS PATENTEBMAY 16 I972 SHEET 5 OF 5'INVENTER GEORG ALTENSTADTER ATTORNEYS APPARATUS FOR THE VIBRATORYFINISHING OF WORKPIECES BACKGROUND OF THE INVENTION The inventionrelates to devices for vibratory barrelling or finishing of workpiecesurfaces whereby relatively large, or a combination of small and largeworkpieces can be processed simultaneously.

Vibratory barrelling machines hitherto used do not satisfy the variedrequirements in the processing of parts of different size, shape andmaterial, such as are generally encountered in every factory.

Thus, it is time-wasting and tedious to remove small parts from largecontainers by separating them from the polishing or abrasive grindingmedium after processing. The separation of the workpieces from thegrinding or polishing media after processing, outside the container,with large-scale magnetic separators or screening devices requirescostly equipment, and causes high operating costs and expensivemaintenance of the auxiliary equipment.

It is a further disadvantage that large and bulky parts, insofar asthese can be processed at all with vibratory finishing machines, canonly be introduced in small numbers per charge to prevent them fromcolliding with each other, from being damaged and from jamming in thecontainers which would impair the normal circulation of the parts andthe polishing medium. In addition, container linings provided forreducing the noise level are frequently damaged or destroyed which canlead to further damage of the parts when they strike unprotected innerwalls of the container during their circulation whereby they can becomedistorted and/or unusable. The use of workpiece positioning or clampingdevices is undesirable because each workpiece requires its own,individually formed device. In addition, a displacement of the center ofgravity is frequently caused by the use of such clamping devices whichcan lead to a premature wear of the machine.

Furthermore, such machines no longer assure the circulation of thegrinding or polishing media so that uniform processing of the entiresurface of the workpieces is imperiled. A further disadvantage of priorart methods is that large workpieces can only be inserted and removedwhile the container is empty. This means that for each operation, whichmay require repeated positioning to assure the uniform processing of thewhole workpiece, valuable time for the repeated emptying and filling ofthe container must be provided which significantly increases the cost offinishing the surfaces of workpieces.

SUMMARY OF THE INVENTION It is an object of the invention to overcomethe above shortcomings and to provide a device whereby relatively largeparts of irregular shape, or a combination of small and large parts, canbe simultaneously processed by a vibratory finishing process withoutdamaging the parts. Other objects are to enable the mounting and removalof the parts without emptying the work container and to eliminate atime-wasting and tedious separating of small parts from the grinding orpolishing media.

According to the invention, this is achieved by mounting an auxiliarydevice to stub shafts extending into the work container. The auxiliarydevice is provided with attachments for the mounting of variously shapedworkpieces. The circulating polishing medium, or an independent drive,move the auxiliary device and the workpieces through the container. Thusthe direction of rotation of the auxiliary device can be determined soas to coincide with or be counter to the direction of the continuouslycirculating polishing medium.

The auxiliary device can be driven via one or more drive shafts and avariable drive gear to enable speed variations of the device for usewith different polishing media and/or workpieces of varying shapes andsizes.

In one embodiment of the present invention the auxiliary devicecomprises pairs of endless roller chains which extend from a sprocket onthe drive shaft into the polishing medium and which are looped oversuitable chain pulleys rotatably mounted on the stub shafts disposedwithin the polishing medium. Various mounting devices for holding theworkpieces and guiding them through the polishing medium are disposedbetween cooperating chain pairs.

In another embodiment of the invention the workpieces are mounted to aframe which is rotatable about the stub shafts and which are defined byradially outwardly extending bars that are interconnected by suitabletransverse stiffeners. The container for the polishing medium ispreferably divided into a plurality of chambers by removable bafflewalls. Alternatively, the baffle walls can be fixedly mounted to thecontainer and provided with closable openings to permit the circulationof the polishing medium through some or all chambers. With the help ofthe closable openings scouring materials and chemical polishing agentscan be distributed through all chambers. A screen is mounted to thelower end of each polishing chamber to separate small, fragmentedparticles of the polishing medium from non-damaged particles.

The present invention further contemplates the provision of cleaning anddrying means outside and above the polishing medium. The cleaning anddrying means are preferably automatically actuated each time a workpiecethat is being removed from the polishing medium passes. In this mannerthe workpieces can be finished, i.e., cleaned and dried, before they areremoved from the auxiliary device. A subsequent handling of theworkpieces is thereby eliminated and substantial cost savings accrue.

Aside from the above referred-to workpiece mounts any one of a number ofpick-up devices are mounted to cooperating chain pairs to removeworkpieces which are not attached to a mount and which are polishedwhile they float within the body of polishing material. Such pick-updevices can comprise screens, grills, magnets and the like.

It has been discovered that the use of glass beads or balls enhances thequality of the finished surfaces of the workpieces. Relatively largeindentations in the surfaces of the finished articles, as are formedwhen steel balls are used as a polishing medium, are thereby eliminated.

To increase the capacity of the vibrating polisher of the presentinvention, a second container can be placed inside the main workcontainer. The second container is constructed so that it has avibration frequency which coincides with that of the main container.While some, say large workpieces are passed through the polishing mediumin the exterior of the second container a mixture of preferably smallworkpieces and a polishing medium is continuously or intermittently fedinto and withdrawn from the second container. Means for decelerating theflow of the mixture through the second container, such as a continuousspirally shaped member can be placed inside the second container to varythe time period during which the workpieces in the mixture are subjectedto the polishing action.

The present invention also provides means for automatically insertingand removing workpieces into and from the main container. Such meanscomprises an endless belt conveyor or the like to which the workpiecesare attached. The belts are suitably guided and pass with the workpiecesmounted thereon continuously or in increments through the polishingmedium in the main container. It is preferred to construct the beltconveyor and supporting structures so that the belt passes throughvarious, integrated work positions such as mounting, preconditioning,finishing, removal, inspection and cleansing positions. At thepreconditioning and finishing stations the belt conveyor can be guidedthrough vibratory conveyors or shakers containing workpieces to beguided to and to be removed from the belt conveyor before and afterbarrel polishing to increase the cost savings provided by the presentinvention.

The present invention further contemplates the means for changing therelative position of the workpieces on the auxiliary device to enhancethe grinding and polishing action on the surfaces of the workpiece. Themounts for the workpieces are so constructed that they permit rotationof the workpieces thereon by engaging intermittently spaced detentsprotruding from the walls of the container or some other suitablypositioned structure. In this manner substantially all surfaces of largeworkpieces face in their direction of movement through the polishingmedium for a part of the time they are subject to the polishing actionwhereby the quality of the finish of the surfaces is increasedirrespective of the size of the workpieces.

To control the time periods during which workpieces are subjected topolishing action an adjustable barrier can be mounted to the container.The barrier is particularly useful in instances where a mixture of smallworkpieces and the polishing medium is discharged into a vibratingconveyor trough. Intermittent removals of relatively large quantities ofsuch workpieces by suitably lowering the barrier are thereby possible.

Endplates of the preferably trough-shaped second container can includeintake and outlet chutes or the like to facilitate the stocking and thewithdrawal of the second container with grinding or polishing mediaand/or with relatively small workpieces. Moreover, if the continuousinsertion and withdrawal of controlled medium and workpiece quantitiesis for some reason undesired or not practical the second container canbe mounted so that it can be raised to.a level where the mixture can bereadily discharged.

The invention will be explained in more detail below with reference tothree examples of embodiments. In the accompanying drawings:

FIG. 1 shows the front view of a first embodiment of the invention;

FIG. 2 shows a side-view of the embodiment illustrated in FIG. 1; v

FIG. 3 shows a front view of a second embodimentof the invention;

FIG. 4 shows a side view of the embodiment illustrated in FIG. 3;

FIG. 5 shows a section through the work container;

FIG. 6 is a diagrammatic illustration of a drum as shown in FIGS. 1 and2;

FIG. 7 is a diagrammatic illustration of the inner face of a drum asshown in FIGS. 1 and 2, including some modificatrons;

FIG. 8 shows,.diagrammatically, a third embodiment of the invention inconjunction with preceding and following processing stages;

FIG. 9 shows a section through one end of the work container illustratedin FIG. 8; and

FIG. 10 shows a section through the other end of the work containerillustrated in FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 and 2, thenumeral 1 designates the work container of a vibratory barrelling orpolishing device for workpieces. The container is filled in a knownmanner with a grinding or polishing medium 19 and is oscillated at therequired frequency by means of a schematically illustrated vibrator V.Depending on the length of work container 1, it is provided with one ormore open or closed partitions 3 each of which may have a slide 4disposed adjacent the lower end of the container for the opening andclosing of an opening communicating adjacent chambers C defined by thepartitions.

The faces of the vibrators, particularly the end walls 2, and of thepartitions 3 preferably include bosses or chequered plates so thatworkpieces, particularly those having relatively large flat surfaces, donot adhere to and concentrate at the faces to assure their participationin the normal operational circulation. Stationary stub axles 6, whichare axially aligned with one another and on which an auxiliary device 7is mounted, are provided in the end walls 2 and/or the partitions 3. Acontinuous shaft can be substituted for the stub axles 6.

In the first embodiment of the invention, the auxiliary device 7consists of three chain pairs 8a-8b, 8c-8d, and 8'e-8f which run overpairs of chain sprockets 9a-9b, 90-911, 9e-9f mounted to drive shafts 11and pairs of chain wheels l0a-l0b, l0c-l0l0e-l0f idling on the stubshafts. A single drive shaft may be provided for all three sprocketpairs or independent drive shafts one for each sprocket pair can bedriven by independently adjustable speed changers to enable the chainpairs to operate at differing speeds. The chain wheels can be replacedby appropriately constructed guide members.

The workpieces 12 are suspended between the chain pairs 8a-8b, 8c-8d,8e-8f through appropriately constructed work receiving attachments ormounts 13, and are thus conveyed through the grinding or polishingmedium 19 as the chains are driven. To permit the universal use of theauxiliary device 7,

the work receiving attachments 13 may be constructed in the form ofattachment elements 13a, such as eyes, springs, angle members ortransverse bars, as screen drums 13b or as magnets 13c.

The rotating chain pairs 8a-8b, 8c-8d, 8e-8f are preferably providedwith pick-up devices 14 such as screens, grates or the like which,together with magnets 13c, serve to pick-up smaller workpieces, freelydisposed in the polishing medium 19, and remove them from the grindingor polishing medium.

Screen drums 13b are intended to receive small and miniature parts. Thedrums are rotatably secured to and between the chain pairs 8a-8b, 8c8d,8e-8f. The mesh size of screen drum 13b may be selectively enlarged orreduced so that the grinding or polishing medium 19 present in the workcontainer 1 can pass through the screen drum 13b. Alternatively, if thedrums are closed grinding and polishing medium is separately introducedinto the drums and remains therein to act on the workpieces. Thus, thescreen drum can be fully closed and separated from the polishing mediumand the polishing particles can be provided with additional cuttingsurfaces or the like to increase their polishing action and to betterutilize their working capacity.

Those grinding or polishing particles which have become too small, as aresult of fracture or splitting, are removed through screening insertsmounted to the bottom of work container 1.

If the partitions 3 are open, there is a common chamber in workcontainer 1. If they are closed, however, and consequently serve aspartitions, then there are three chambers. In both cases, theoscillations produced by the vibrator V are transmitted to the contentsof the container the grinding or polishing medium and the workpieces 12and impart to them the required circulatory motion by appropriatematching of the frequency and the amplitude of the vibrations. As aresult of the separate drive, for each of the chain pairs 8a-8b, 8c-8dand 8e-8f, they can be given different driving speeds, to obtainvariable grinding and polishing capacities. By deactivating spraying anddrying devices 15, 16, one or more chain pairs can be driven in anopposite direction to obtain a counterflow between the circulation ofthe grinding or polishing medium and the moving workpieces.

Referring to FIGS. 3 and 4, a second embodiment of the inventionprovides an auxiliary device 7a defined by a frame rotatably mounted onstub axles 6 or on a continuous axle (not shown). The frame comprisesrods 17 which extend radially from a hub 7b, substantially in the formof a star, and which are connected to one another by means of axialtransverse rods 18 and circumferentially arranged rods 18a situated inthe plane of radial rods 17 to thereby increase the rigidity of theframe. Work receiving attachments 13 are secured to rods 17, 18 and 18aand, as in the first example, preferably comprise attachment members13a, screen drums 13b or magnets 13c (not illustrated in FIGS. 3 and 4).Although the auxiliary device 7a is illustrated as comprising a unitaryframe it can be constructed as a plurality of independently mounted,smaller frames. The frame is disposed inside container la and is rotatedabout the stub shafts by the circulating motion of the polishing mediumor it is power driven with a separate drive (not shown).

Referring to FIG. 1 and 2, agglomeration of the parts is counteracted byproviding a longitudinally grooved roll 20 or the like, preferablyconstructed of rubber or plastics, which is rotatably mounted in the twoend walls 2 of the container and/or in the partitions 3. The circulationof the polishing medium rotates the roll whereby the above referred-toagglomeration is prevented.

Referring to FIG. 5, work container 1 can be surrounded by a jacket 21and a sound-absorbing medium 22 in the cavity between the container walland the jacket. A mixture of foam rubber and latex may be used as suchmedium for example, which can be cured or vulcanized after the foamedstructure has been positioned to provide a permanent acousticinsulation.

Referring to FIG. 6, thermoplastic or molded rubber workpieces arepreferably placed into double walled, so called Dewar vessels for theirsurface finishing. A gap 23 between the two walls is vacuumized tothermally insulate the interior of the drums. The plastic or moldedrubber parts are supercooled before they are placed in the drums andremain in that state as a result of the drums insulating effect. Such anarrangement is necessary since the deburring and surface finishing ofplastic and molded rubber parts by vibratory barrelling is only possibleif they are in the supercooled state because only then do the parts havethe necessary brittleness. If plastic parts are to have a non-glossy ormatt finish, the inner wall of the drum may be roughened, for example byproviding it with a lining 24 similar to a file cleaner, a lining 25similar to a reaming tool, or a kind ofsandpaper 26 (FIG. 7).

The linings 24, 25 or 26 prevent the formation of a high gloss surfacefinish of the plastic parts as they glide past the linings.

Referring to FIG. 8, a third embodiment of the invention comprises awork container lb of a vibratory barrelling or polishing apparatus andforms part of a system which includes an auxiliary device 7d, aprocessing container 27 and other special equipment as more fully setforth hereinafter. The entire system consists of, apart from workcontainer lb, an assembly stage I, a pretreatment stage II, a finishingstage III, a dismounting stage IV and a control and cleaning stage V.Within this entire system, transport and guide means 34 to 38 ensure acontinuous, uninterrupted flow of grinding or polishing medium as isnecessary in a closed production line.

The assembly-line type auxiliary device 7d is mainly for handling largeworkpieces, comprises belts, chains or the like, is guided over guidemembers or pulleys 30, guide and tensioning pulleys 31 and idler pulleys48 and permits the interruption or repetition of the processing steps inaccordance with particular requirements for the workpieces beingprocessed. Work receiving attachments 13 are provided for securingindividual workpieces to auxiliary device 7d for conveying the largerworkpieces economically to and through the processing sections. Grooves50 and 51 disposed in the end plates of the container (see FIGS. 9 andguide the belts or chains of the auxiliary device through work container1b.

The work receiving attachments 13 on the auxiliary device 7d preferablyinclude indexing members 39 which, on contact with stops 40 mounted towork container 1b, cause a rotational movement of the attachments andthereby positively change the position of workpieces 49 secured thereto.The workpiece holding attachments may comprise magnetic carriers whichcan be magnetized at a given point to receive and hold a workpiece anddemagnetized at another point to release the processed parts.

Adjustable shaker or vibrating conveyor troughs 32 and 33 are mountedupstream and downstream of work container 1b and are disposed at suchelevations that the auxiliary device 7d runs through them. At the entryto shaker trough 32, there is provided a guide device or chute 38 whichcan supply a mixture of workpieces 28 of relatively small dimensions andgrinding or polishing medium 19. The mixture enters work container lbvia vibration conveyor trough 32 of the preprocessing stage II, throughvibratory action, and is transferred to the vibratory conveyor trough 33at the finishing stage III over the adjustable overflow bar 41. A screen53 positioned at the end of trough 33 separates the grinding orpolishing medium 19 from workpieces 28 and the latter are dischargedthrough a chute 52. The separated grinding or polishing medium 19 dropsthrough an upright, tubular conveying device 34 onto a belt conveyor 35and it is returned to vibrating conveyor trough 32 by a vertical wormtransport device 36. workpieces 28 discharged by trough 52 are removedby a belt conveyor 37. If desired, screen 53 can be replaced by amagnetic separator.

Referring to FIGS. 8l0, apart from the auxiliary device 7d, a secondprocessing container 27 which has a generally snail shape configurationis mounted in work container lb, preferably on its stub axles 6. Theprocessing container 27 is provided with a closing cover 27a whichseparates the contents of the processing container 27 from the othercontents of work container 1b and, at the same time, acts as a bridgingmeans during the emptying of the contents of the processing container 27into the vibrating conveyor trough 33 when the processing container iselevated to its uppermost position by suitable lifting means L. Theprocessing container 27 may be provided with one or more partitions (notillustrated) for the processing of workpieces requiring differingprocessing conditrons.

To increase the capacity and economy of the polishing apparatusillustrated in FIGS. 8-10, a horizontal cylindrical tube T can beinstalled instead of processing container 27. The tube is secured towork container 1b with its ends 43 and 44 carried by stub axles 6, andincludes intake and discharge chutes 46, 47, respectively, for placing amixture of small workpieces 28 and polishing medium into and removing itfrom tube T. The cylindrical tube can be provided with a fixed shaft 5which rigidly mounts a spiral-shaped insert 29. The firmly mountedinsert 29 and the vibration ensure that the parts-polishing mediummixture advances relatively slowly from the adjustable intake chute 46,through an aperture 44, the cylindrical tube T, an aperture 45, and outthrough discharge chute 47.

To enable the processing of very small parts, the inner wall ofcylindrical tube T can be equipped with a helical, inwardly protrudingstrip (not shown). In this case, in contrast to the previously describedmodification, the cylindrical tube is open ended so that smallcylindrical containers (not shown) having helical grooves in their outerwalls can be inserted in the cylindrical tube. As a result of thevibration and of the matching pitch of the helical band in thecylindrical tube and the helical groove on the cylindrical containers,they travel slowly through the cylindrical tube while a rotating actionis imparted to them.

As a further alternative embodiment of the invention, stub axles 6 ofthe work container can be constructed as cylindrically hollow stubshafts which communicate to the exterior of the container and mount asuitable rotary drum which can thus be placed into the interior of thework container. Suitable means, such as one of the chain pairs 8a8bthrough 82-8], or independent drive means, can be provided for rotatingthe drum. This has the advantage that in addition to the vibratorybarrelling of the workpieces, the workpieces are also subjected to arotary surface finishing action. Better surface finishing and/or ahigher capacity is thereby obtained. In this embodiment the abovedescribed helical, inwardly protruding strip and cylindrical throughputcontainers having matching helical grooves to control and vary the speedwith which the workpieces move through the rotating drum can beincluded.

Although only indicated above, nevertheless, it is within the scope ofthe invention for smaller closable containers to be introduced into theprocessing container 27 as well as for the processing container 27 to bereplaced either by a cylindrical tube with a helical insert 29 for thepurpose of the axial throughput of the mixture of parts and grinding orpolishing medium or the cylindrical containers can be axially conveyed,by force, through the cylindrical tube which is then open. The entiresystem may, of course, also be extended so that further processingstations are included between the described processing stages I to V,or, for example, for the additional machining of workpieces 49 and 28.

What is claimed is:

1. Apparatus for treating surfaces of workpieces comprising: a containerfor receiving a fluid surface treating medium, the container includingpartition means forming a plurality of work chambers, and means forestablishing communication between adjacent chambers across thepartition means, means for subjecting the medium to vibrations forcirculating the medium in the container, means movable into and out of acontainer portion receiving the medium and mounted to the container,means for mounting workpieces to the movable means, whereby theworkpieces can move through the vibrating medium and be removedtherefrom, and screen means mounted 'at the bottom of each chamber forseparating damaged particles of the medium from the remainder of themedium.

2. Apparatus according to claim 1 wherein the workpiece mounting meanscomprising drums, magnets and means for mechanically securing theworkpieces to the movable means.

3. Apparatus according to claim 1 including at least one elongate memberhaving a plurality of sharp, longitudinally .extending exterior edgesand means for rotatably mounting the member to the container and withinthe container portion holding the medium to prevent the agglomeration ofworkpieces floating in the medium.

4. Apparatus according to claim 1 wherein the workpiece mounting meanscomprises closed drums including means forming a vacummized, airtight,temperature-insulating jacket around an interior of the drum to enablethe surface treating of thermoplastic materials under low temperatures.

5. Apparatus according to claim 1 wherein the workpiece mounting meanscomprises drums having roughened interior surfaces of a hardnessexceeding the hardness of the workpieces for obtaining dull surfacefinishes on the workpieces.

6. Apparatus for treating surfaces of workpieces comprising: a firstcontainer for receiving a fluid surface treating medium, means forsubjecting the container to vibrations for transfer of the vibrations tothe medium to thereby circulate the medium in the first container, asecond container disposed interiorly of and connected to the firstcontainer for receiving a mixture of relatively small workpieces and asurface treating medium, means for introducing the mixture into thesecond container and for withdrawing the mixture therefrom, the secondcontainer having a configuration whereby the vibration frequency of thefirst container causes a movement of the mixture through the secondcontainer, and an auxiliary device movably carried by the firstcontainer and including means for mounting relatively larger workpiecesfor moving the larger workpieces into, through and out of the medium inthe first container.

7. Apparatus according to claim 6 including vibrating troughs disposedadjacent the first container, and means for guiding the workpiecescarried by the auxiliary device through the troughs for further treatingthe surfaces of the relatively larger workpieces.

8. Apparatus according to claim 6 wherein the auxiliary device includesband means carrying the workpiece mounting means, and further includingguide means for the band means for guiding the band means in an endlessloop through a plurality of additional work stations for completingadditional process steps on the larger workpieces.

9. Apparatus according to claim 6 wherein the workpiece mounting meanscomprises conveyor means, workpiece holding means, means for rotatablyconnecting the holding means to the conveyor means and projection meansfixedly connected to the first container for rotating the holding meansand intermittently repositioning the workpieces with respect to theirdirection of movement.

10. Apparatus according to claim 6 wherein the auxiliary device includesconveyor means, and including barrier means disposed adjacent a portionof the conveyor leaving the first container for raising and lowering thelevel of the medium in the first container.

11. Apparatus according to claim 6 wherein ends of the second containerinclude openings for admitting and withdrawing the mixture to and fromthe second conveyor,

and including chute means aligned with the second container and mountedto end walls of the first container for admitting the mixture into thesecond container from the exterior of the first container and forwithdrawing the mixture from the second container to the exterior of thefirst container.

12. Apparatus according to claim 6 including means for raising thesecond container from its normal working position to a position adjacenta workpiece withdrawal opening in the first container to permit theplacement of the mixture in and the withdrawal of the mixture from thesecond container.

13. Apparatus according to claim 6 including hollow shaft means mountedto the first container, means for suitably mounting the second containerto the hollow shaft means, and means for rotating the second containerabout the shaft means to additionally subject the mixture to rotarymotions and the workpiece surfaces to rotary drum finishing.

1. Apparatus for treating surfaces of workpieces comprising: a containerfor receiving a fluid surface treating medium, the container includingpartition means forming a plurality of work chambers, and means forestablishing communication between adjacent chambers across thepartition means, means for subjecting the medium to vibrations forcirculating the medium in the container, means movable into and out of acontainer portion receiving the medium and mounted to the container,means for mounting workpieces to the movable means, whereby theworkpieces can move through the vibrating medium and be removedtherefrom, and screen means mounted at the bottom of each chamber forseparating damaged particles of the medium from the remainder of themedium.
 2. Apparatus according to claim 1 wherein the workpiece mountingmeans comprising drums, magnets and means for mechanically securing theworkpieces to the movable means.
 3. Apparatus according to claim 1including at leAst one elongate member having a plurality of sharp,longitudinally extending exterior edges and means for rotatably mountingthe member to the container and within the container portion holding themedium to prevent the agglomeration of workpieces floating in themedium.
 4. Apparatus according to claim 1 wherein the workpiece mountingmeans comprises closed drums including means forming a vacummized,airtight, temperature-insulating jacket around an interior of the drumto enable the surface treating of thermoplastic materials under lowtemperatures.
 5. Apparatus according to claim 1 wherein the workpiecemounting means comprises drums having roughened interior surfaces of ahardness exceeding the hardness of the workpieces for obtaining dullsurface finishes on the workpieces.
 6. Apparatus for treating surfacesof workpieces comprising: a first container for receiving a fluidsurface treating medium, means for subjecting the container tovibrations for transfer of the vibrations to the medium to therebycirculate the medium in the first container, a second container disposedinteriorly of and connected to the first container for receiving amixture of relatively small workpieces and a surface treating medium,means for introducing the mixture into the second container and forwithdrawing the mixture therefrom, the second container having aconfiguration whereby the vibration frequency of the first containercauses a movement of the mixture through the second container, and anauxiliary device movably carried by the first container and includingmeans for mounting relatively larger workpieces for moving the largerworkpieces into, through and out of the medium in the first container.7. Apparatus according to claim 6 including vibrating troughs disposedadjacent the first container, and means for guiding the workpiecescarried by the auxiliary device through the troughs for further treatingthe surfaces of the relatively larger workpieces.
 8. Apparatus accordingto claim 6 wherein the auxiliary device includes band means carrying theworkpiece mounting means, and further including guide means for the bandmeans for guiding the band means in an endless loop through a pluralityof additional work stations for completing additional process steps onthe larger workpieces.
 9. Apparatus according to claim 6 wherein theworkpiece mounting means comprises conveyor means, workpiece holdingmeans, means for rotatably connecting the holding means to the conveyormeans and projection means fixedly connected to the first container forrotating the holding means and intermittently repositioning theworkpieces with respect to their direction of movement.
 10. Apparatusaccording to claim 6 wherein the auxiliary device includes conveyormeans, and including barrier means disposed adjacent a portion of theconveyor leaving the first container for raising and lowering the levelof the medium in the first container.
 11. Apparatus according to claim 6wherein ends of the second container include openings for admitting andwithdrawing the mixture to and from the second conveyor, and includingchute means aligned with the second container and mounted to end wallsof the first container for admitting the mixture into the secondcontainer from the exterior of the first container and for withdrawingthe mixture from the second container to the exterior of the firstcontainer.
 12. Apparatus according to claim 6 including means forraising the second container from its normal working position to aposition adjacent a workpiece withdrawal opening in the first containerto permit the placement of the mixture in and the withdrawal of themixture from the second container.
 13. Apparatus according to claim 6including hollow shaft means mounted to the first container, means forsuitably mounting the second container to the hollow shaft means, andmeans for rotating the second container about the shaft means toadditionally subject the mixture to rotary motions and the workpiecEsurfaces to rotary drum finishing.